Rootstocks for Apple Trees

Parts of a grafted apple tree.Photo courtesy of eApples (www.extension.org/apples)

Commercial orchards in Minnesota may have trees on standard, semi-dwarf, and/or dwarf rootstocks. While dwarf trees have many advantages over larger trees, there are a number of reasons for orchardists continuing to grow apples on standard rootstocks. If the trees were planted many years ago, they are likely to be on standard rootstocks. If they have been maintained and are producing well, orchardists are likely to continue cropping these large trees, in spite of the difficulties in pruning, training, controlling pests, and harvesting these blocks.

Many trees in Minnesota orchards are on the semi-dwarf rootstock M7, because locally grown trees on this rootstock have been available for years. As growers plant new orchards or replace blocks, however, they are planting primarily dwarf trees on rootstocks such as M9, Bud9, and M26. Research by growers and the University of Minnesota has shown these to be best suited to profitable production in the state.